1. Field of the Invention
The present invention relates to an antenna unit used by being attached to a body that is to be detected such as a CD-ROM or a DVD-ROM including a conductive member. A wireless communication structure equipped with the body includes the conductive member and an antenna that is attached to the body, and an antenna structure applied to the body includes the conductive member and a non-conductive member.
2. Related Art
A disc changer is known as a device for managing/searching a body to be detected such as a disc shaped recording medium like a CD-ROM or a DVD-ROM. However, since the disc changer is configured to identify the recording medium by an arrangement order etc. of the recording medium, it is not possible to search the recording medium while checking the content of the same with the disc changer. Furthermore, the number of recording media to be accommodated is defined in the disc changer, and thus a great number of recording media cannot be handled.
In particular, there are many cases to save various records as electronic data in recent years, and the amount of such data has been becoming a vast amount. Therefore, a great number of recording media must be kept, and it is needed to rapidly and reliably perform inventory management, housing management, access management, or search for managed and kept recording media with respect to such a great number of recording media.
There is another known configuration used in collection management of books or the like. The configuration utilizes an RF-ID element including an IC chip and the antenna, and is configured so that the antenna transmits information stored in the IC chip (see e.g., Japanese unexamined patent publication No. H10-334198).
However, in a case where the recording medium includes a conductive deposition film made of aluminum etc. such as CD-ROMs and DVD-ROMs, inventory management is performed by utilizing an antenna attached to the recording medium, and the conductive deposition film can interfere with the signals that the antenna transmits and receives. Such interference affects a radiating property of the transmitted signal by the antenna, thereby a correct signal cannot be transmitted or received.